# Pulse-width Modulated DC-DC Power Converters

# Pulse-width Modulated DC-DC Power Converters

ISBN: 978-0-470-69465-7

Sep 2008

808 pages

$136.99

## Description

This book studies switch-mode power supplies (SMPS) in great detail. This type of converter changes an unregulated DC voltage into a high-frequency pulse-width modulated (PWM) voltage controlled by varying the duty cycle, then changes the PWM AC voltage to a regulated DC voltage at a high efficiency by rectification and filtering. Used to supply electronic circuits, this converter saves energy and space in the overall system.With concept-orientated explanations, this book offers state-of-the-art SMPS technology and promotes an understanding of the principle operations of PWM converters, as well as enabling the reader~~s~~ to evaluate their characteristics. Design-orientated analysis (including a steady-state analysis for both continuous and discontinuous conduction modes) and numerous real-world practical examples (including circuit models of the PWM converters) demonstrate how to design these from scratch.

The book provides an in-depth presentation of topologies of PWM DC-DC power converters, voltage- and current-mode control of PWM DC–DC power converters, considers power losses in all components, device stresses, output voltage ripple, converter efficiency and power factor correction (PFC). It also includes extensive coverage of the following:

- topologies of high-efficiency switching-mode PWM and soft-switching DC-DC power converters;
- DC voltage transfer functions (conversion ratios), component values, losses, efficiency, and stresses;
- small-signal averaged circuit models;
- current-mode and voltage-mode feedback controls;
- metal-oxide-semiconductor field-effect power transistors (MOSFETs);
- silicon (Si) and silicon carbide (SiC) power semiconductor devices. Before now, there has been no book that covers silicon carbide devices.

*Pulse-width Modulated DC-DC Power Converters* is a comprehensive textbook for senior undergraduate and graduate students in the areas of electrical, electronics, and telecommunications engineering. It includes end-of-chapter review questions, problems, and thorough summaries of the key concepts to aid learning, and a *Solutions Manual* is available for professors. Scientists and practicing design engineers working with SMPS, within such applications as computers, telecommunications, industrial systems, automobile electronics, medical equipment, aerospace power technology, and radars (amongst others) will also find this text insightful.

**Preface.**

**About the Author.**

**List of Symbols.**

**1 Introduction.**

1.1 Classification of Power Supplies.

1.2 Basic Functions of Voltage Regulators.

1.3 Power Relationships in DC–DC Converters.

1.4 DC Transfer Functions of DC–DC Converters.

1.5 Static Characteristics of DC Voltage Regulators.

1.6 Dynamic Characteristics of DC Voltage Regulators.

1.7 Linear Voltage Regulators.

1.8 Topologies of PWM DC–DC Converters

1.9 Relationships among Current, Voltage, Energy, and Power.

1.10 Electromagnetic Compatibility.

1.11 Summary.

1.12 References.

1.13 Review Questions.

1.14 Problems.

**2 BuckPWMDC–DCConverter.**

2.1 Introduction.

2.2 DC Analysis of PWM Buck Converter for CCM.

2.3 DC Analysis of PWM Buck Converter for DCM.

2.4 Buck Converter with Input Filter.

2.5 Buck Converter with Synchronous Rectifier.

2.6 Buck Converter with Positive Common Rail.

2.7 Tapped-Inductor Buck Converters.

2.8 Multiphase Buck Converter.

2.9 Summary.

2.10 References.

2.11 Review Questions.

2.12 Problems.

**3 Boost PWM DC–DC Converter.**

3.1 Introduction.

3.2 DC Analysis of PWM Boost Converter for CCM.

3.3 DC Analysis of PWM Boost Converter for DCM.

3.4 Bidirectional Buck and Boost Converters.

3.5 Tapped-Inductor Boost Converters.

3.6 Duality.

3.7 Power Factor Correction.

3.8 Summary.

3.9 References.

3.10 Review Questions.

3.11 Problems.

**4 Buck-Boost PWM DC–DC Converter.**

4.1 Introduction.

4.2 DC Analysis of PWM Buck-Boost Converter for CCM.

4.3 DC Analysis of PWM Buck-Boost Converter for DCM.

4.4 Bidirectional Buck-Boost Converter.

4.5 Synthesis of Buck-Boost Converter.

4.6 Synthesis of Boost-Buck (Cuk) Converter.

4.7 Noninverting Buck-Boost Converters.

4.8 Tapped-Inductor Buck-Boost Converters.

4.9 Summary.

4.10 References.

4.11 Review Questions.

4.12 Problems.

**5 Flyback PWM DC–DC Converter.**

5.1 Introduction.

5.2 Transformers.

5.3 DC Analysis of PWM Flyback Converter for CCM.

5.4 DC Analysis of PWM Flyback Converter for DCM.

5.5 Multiple-Output Flyback Converter.

5.6 Bidirectional Flyback Converter.

5.7 Ringing in Flyback Converter.

5.8 Flyback Converter with Active Clamping.

5.9 Two-Transistor Flyback Converter.

5.10 Summary.

5.11 References.

5.12 Review Questions.

5.13 Problems.

**6 Forward PWM DC–DC Converter.**

6.1 Introduction.

6.2 DC Analysis of PWM Forward Converter for CCM.

6.3 DC Analysis of PWM Forward Converter for DCM.

6.4 Multiple-Output Forward Converter.

6.5 Forward Converter with Synchronous Rectifier.

6.6 Forward Converters with Active Clamping.

6.7 Two-Switch Forward Converter.

6.8 Summary.

6.9 References.

6.10 Review Questions.

6.11 Problems.

**7 Half-Bridge PWM DC–DC Converter.**

7.1 Introduction.

7.2 DC Analysis of PWM Half-Bridge Converter for CCM.

7.3 DC Analysis of PWM Half-Bridge Converter for DCM.

7.4 Summary.

7.5 References.

7.6 Review Questions.

7.7 Problems.

**8 Full-Bridge PWM DC–DC Converter.**

8.1 Introduction.

8.2 DC Analysis of PWM Full-Bridge Converter for CCM.

8.3 DC Analysis of PWM Full-Bridge Converter for DCM.

8.4 Phase-Controlled Full-Bridge Converter.

8.5 Summary.

8.6 References.

8.7 Review Questions.

8.8 Problems.

**9 Push-Pull PWM DC–DC Converter.**

9.1 Introduction.

9.2 DC Analysis of PWM Push-Pull Converter for CCM.

9.3 DC Analysis of PWM Push-Pull Converter for DCM.

9.4 Comparison of PWM DC–DC Converters.

9.5 Summary.

9.6 References.

9.7 Review Questions.

9.8 Problems.

**10 Small-Signal Models of PWM Converters for CCM** **and DCM.**

10.1 Introduction.

10.2 Assumptions.

10.3 Averaged Model of Ideal Switching Network for CCM.

10.4 Averaged Values of Switched Resistances.

10.5 Model Reduction.

10.6 Large-Signal Averaged Model for CCM.

10.7 DC and Small–Signal Circuit Linear Models of Switching Network for CCM.

10.8 Family of PWM Converter Models for CCM.

10.9 PWM Small-Signal Switch Model for CCM.

10.10 Modeling of the Ideal Switching Network for DCM.

10.11 Averaged Parasitic Resistances for DCM.

10.12 Small-Signal Models of PWM Converters for DCM.

10.13 Summary.

10.14 References.

10.15 Review Questions.

10.16 Problems.

**11 Open-Loop Small-Signal Characteristics of Boost** **Converter for CCM.**

11.1 Introduction.

11.2 DC Characteristics.

11.3 Open-Loop Control-to-Output Transfer Function.

11.4 Delay in Open-Loop Control-to-Output Transfer Function.

11.5 Open-Loop Audio Susceptibility.

11.6 Open-Loop Input Impedance.

11.7 Open-Loop Output Impedance.

11.8 Open-Loop Step Responses.

11.9 Summary.

11.10 References.

11.11 Review Questions.

11.12 Problems.

**12 Voltage-Mode Control of Boost Converter.**

12.1 Introduction.

12.2 Circuit of Boost Converter with Voltage-Mode Control.

12.3 Pulse-Width Modulator.

12.4 Transfer Function of Modulator, Boost Converter Power Stage, and Feedback Network.

12.5 Error Amplifier.

12.6 Integral-Single-Lead Controller.

12.7 Integral-Double-Lead Controller.

12.8 Loop Gain.

12.9 Closed-Loop Control-to-Output Voltage Transfer Function.

12.10 Closed-Loop Audio Susceptibility.

12.11 Closed-Loop Input Impedance.

12.12 Closed-Loop Output Impedance.

12.13 Closed-Loop Step Responses.

12.14 Closed-Loop DC Transfer Functions.

12.15 Summary.

12.16 References.

12.17 Review Questions.

12.18 Problems.

**13 Current-Mode Control.**

13.1 Introduction.

13.2 Principle of Operation of PWM Converters with Peak-Current-Mode Control.

13.3 Relationship between Duty Cycle and Inductor-Current Slopes.

13.4 Instability of Closed-Current Loop.

13.5 Slope Compensation.

13.6 Sample-and-Hold Effect on Current Loop.

13.7 Current Loop in *s*-Domain.

13.8 Voltage Loop of PWM Converters with Current-Mode Control.

13.9 Feedforward Gains in PWM Converters with Current-Mode Control without Slope Compensation.

13.10 Feedforward Gains in PWM Converters with Current-Mode Control and Slope Compensation.

13.11 Closed-Loop Transfer Functions with Feedforward Gains.

13.12 Slope Compensation by Adding a Ramp to Inductor Current.

13.13 Relationships for Constant-Frequency Current-Mode On-Time Control.

13.14 Summary.

13.15 References.

13.16 Review Questions.

13.17 Problems.

13.18 Appendix: Sample-and-Hold Modeling.

**14 Current-Mode Control of Boost Converter.**

14.1 Introduction.

14.2 Open-Loop Small-Signal Transfer Functions.

14.3 Open-Loop Step Responses of Inductor Current.

14.5 Closed-Voltage-Loop Transfer Functions.

14.6 Closed-Loop Step Responses.

14.7 Closed-Loop DC Transfer Functions.

14.8 Summary.

14.9 References.

14.10 Review Questions.

14.11 Problems.

**15 Silicon and Silicon Carbide Power Diodes.**

15.1 Introduction.

15.2 Electronic Power Switches.

15.3 Intrinsic Semiconductors.

15.4 Extrinsic Semiconductors.

15.5 Silicon and Silicon Carbide.

15.6 Physical Structure of Junction Diodes.

15.7 Static *I* –*V* Diode Characteristic.

15.8 Breakdown Voltage of Junction Diodes.

15.9 Capacitances of Junction Diodes.

15.10 Reverse Recovery of pn Junction Diodes.

15.11 Schottky Diodes.

15.12 SPICE Model of Diodes.

15.13 Summary.

15.14 References.

15.15 Review Questions.

15.16 Problems.

**16 Silicon and Silicon Carbide Power MOSFETs.**

16.1 Introduction.

16.2 Physical Structure of Power MOSFETs.

16.3 Principle of Operation of Power MOSFETs.

16.4 Derivation of Power MOSFET Characteristics.

16.5 Power MOSFET Characteristics.

16.6 Mobility of Charge Carriers.

16.7 Short-Channel Effects.

16.8 Aspect Ratio of Power MOSFETs.

16.9 Breakdown Voltage of Power MOSFETs.

16.10 Gate Oxide Breakdown Voltageof Power MOSFETs.

16.11 Resistance of Drift Region.

16.12 Figures-of-Merit.

16.13 On-Resistance of Power MOSFETs.

16.14 Capacitances of Power MOSFETs.

16.15 Switching Waveforms.

16.16 SPICE Model of Power MOSFETs.

16.17 Insulated Gate Bipolar Transistors.

16.18 Heat Sinks.

16.19 Summary.

16.20 References.

16.21 Review Questions.

16.22 Problems.

**17 Soft-Switching DC–DC Converters.**

17.1 Introduction.

17.2 Zero-Voltage-Switching DC–DC Converters.

17.3 Buck ZVS Quasi-Resonant DC–DC Converter.

17.4 Boost ZVS Quasi-Resonant DC–DC Converter.

17.5 Zero-Current-Switching DC–DC Converters.

17.6 Boost ZCS Quasi-Resonant DC–DC Converter.

17.7 Multiresonant Converters.

17.8 Summary.

17.9 References.

17.10 Review Questions.

17.11 Problems.

**Appendix A Introduction to SPICE.**

**Appendix B Introduction to MATLAB.**

**Answers to Problems.**

**Index.**